Bulk and surface plasmon excitation in the interaction of He þ with Mg surfaces

Size: px
Start display at page:

Download "Bulk and surface plasmon excitation in the interaction of He þ with Mg surfaces"

Transcription

1 Nuclear Instruments and Methods in Physics Research B 212 (23) Bulk and surface plasmon excitation in the interaction of He þ with Mg surfaces P. Riccardi a,b, *, A. Sindona a, P. Barone a, A. Bonanno a, A. Oliva a, R.A. Baragiola b a Laboratory for Atomic and Surface Physics, University of Virginia, Engineering Physics, 2291 Charlottesville, Virginia, USA b Laboratorio IIS, Dipartimento di Fisica, Universita della Calabria and INFM Unita di Cosenza, 8736 Arcavacata di Rende, Cosenza, Italy Abstract We report on studies of plasmon excitation in Mg under the impact of slow He þ ions in the incident energy range.1.5 kev. Consistent with studies on Al surfaces, a transition from surface to bulk plasmon excitation occurs as the energy of the ion is increased. Previous methods in the literature to obtain information about yields of electron emission from plasmon decay are discussed. A new data analysis procedure is presented, which allows disentangling the contributions to the experimental spectra arising from different emission mechanisms, showing that potential excitation of multipole surface plasmons gives an important contribution to electron emission. Ó 23 Elsevier B.V. All rights reserved. 1. Introduction Neutralization by electron capture of slow ions at metal surfaces releases potential energy that can excite plasmons [1], quantized collective oscillations of the metal charge density. Plasmons of energy E pl can be excited if E n E pl, where E n is the potential energy transferred to the solid. The excited plasmons then decay by excitation of valence electrons resulting in electron emission, which is experimentally identified by a characteristic structure produced in the energy distribution of emitted electrons. This structure shows a highenergy edge at E m ¼ E pl U [1,2], where U is the * Corresponding author. address: riccardi@fis.unical.it (P. Riccardi). metal work function, corresponding to the emission of an electron from the Fermi level. Plasmon excitation and decay competes with the well-known mechanisms for potential electron emission at metal surfaces [3,4]: Auger neutralization, that involves two electrons from the solid, and resonant neutralization followed by interatomic Auger deexcitation. Since the work by Baragiola and Dukes [5], suggesting that electron emission from plasmon decay is more important than Auger neutralization, several investigation [6 12] have been performed to study potential electron emission from free electron metals, but the question of the competition between plasmon excitation and Auger processes has not yet been answered. Most of the studies of potential plasmon excitation have considered ion impact on Al surfaces X/$ - see front matter Ó 23 Elsevier B.V. All rights reserved. doi:1.116/s x(3)1424-1

2 34 P. Riccardi et al. / Nucl. Instr. and Meth. in Phys. Res. B 212 (23) The difficulty in experiments on Al samples is the strong overlap in the plasmon and Auger structures in the electron energy spectra. The Auger neutralization structure has a maximum energy at E b ¼ I 2U, where I is the ionization potential of the parent atom shifted by the image interaction. This structure is thus separated in energy from the plasmon by I U E pl. Furthermore, the distinction between the two structures can be done by observing the different behavior of the broadening of the Auger and the plasmon structure with changes in the ion velocity [7]. In Al, the two structures can be distinguished only in the case of incident He þ ions [5,1], while for Ar þ ions no plasmon structure is observed [7], and for Ne þ no clear Auger structure has been resolved [5,7,8]. In contrast, the spectra of electron emission from Mg surfaces by slow ions carrying high potential energy, such as He þ and Ne þ, show that the plasmon decay and the Auger structures are clearly separated in energy [1], due to the lower energy of the plasmons of Mg. Experiments on Mg surfaces appear, then, to be better suited to study the role of plasmon decay in potential electron emission. To this end, we measured energy distribution of electrons emitted from Mg surfaces under the impact of slow He þ ions. Consistent with previous research [7,8], the plasmon structure observed in the spectra induced by slow He þ ions is attributed to decay of multipole surface plasmons [9] excited by the potential energy released by the neutralization at the surface of incoming ions. Bulk plasmon excitation appears at our highest impact energies. We discuss methods to extract yields of electrons from plasmon decay from the experimental spectra. A very simple data analysis procedure allows disentangling the contribution given by multipole plasmon decay from that by Auger processes and from a low energy peak due to electronic collision cascade. 2. Experiments The experiments were performed in an ultra high vacuum (base pressure Torr) surface science system used in previous electron emission studies [5], using a double-pass, cylindrical mirror, electron energy spectrometer. The spectrometer was operated at constant pass energy of 5 ev and a resolution of.2 ev. The energy scale was calibrated to refer to the vacuum level of the Mg sample [5]. The surface of the sample was normal to the axis of the spectrometer and at 12 with respect to the ion beam direction. Ions were produced in an electron impact source, which was operated at an electron energy of 58 ev. The polycrystalline Mg surface was sputter cleaned by 4 kev Ar þ ion bombardment and cleaning was monitored by ion and electron induced Auger electron spectroscopy. 3. Results In the upper panel of Fig. 1, we report energy distributions N ðeþ of electrons emitted by the Mg surface under the impact of ev He þ ions. The spectra in Fig. 1 have been normalized so that their area equals the electron emission yield c tot as in [5], being consistent with those previous studies. They show two structures labeled a and b, superimposed on a background peak of cascade electrons [4]. These structures appear clearer in the derivative of the spectra shown in the lower panel of Fig. 1. The energy of the structure b is consistent with the energy E b ¼ I 2U (U ¼ 3:75 ev is the work function for polycrystalline Mg) expected for the high-energy edge of the spectrum of the electrons emitted from the Mg surface by Auger neutralization. This attribution is confirmed by the observed broadening of the electron energy distributions N ðeþ with increasing projectile energy (see inset in Fig. 1). This broadening is typical of neutralization via Auger processes and results from the atomic energy level shift near the surface and incomplete adiabaticity due to ion motion normal to the surface [13]. Furthermore, the spectra shown in Fig. 1 intersect at a magical point [14], another characteristic of velocity broadened Auger spectra, which corresponds to the minimum of the structure b observed in the derivative.

3 P. Riccardi et al. / Nucl. Instr. and Meth. in Phys. Res. B 212 (23) N(E) (e/ev) b 16 ev 26 ev 36 ev 46 ev (a).4 kev (e) -2.4 kev N(E) (e/ev) a b 16 ev 26 ev 36 ev 46 ev -5-2 (b) 1 kev (f) 1keV dn/de (1 e/ev 2 ) -5 a b 16 ev 26 ev 36 ev 46 ev dn/de (1 e/ev 2 ) (c) 2.5keV (g) 2.5keV Kinetic Energy (ev) Fig. 1. Top: Energy spectra NðEÞ of electrons emitted by the Mg surface by impact of ev He þ ions. Bottom: Derivative dnðeþ=de that enhances the structure due to plasmon decay and Auger neutralization. The derivatives are arbitrarily displaced in the vertical scale for clarity. The structures labeled a and b and approximately marked by vertical lines indicate respectively the edge of the plasmon decay and Auger features (d) 4keV (h) Energy (ev) 4 kev The structure labeled a does not depend on the ionization potential of the incoming ions [5]. Consistent with studies [7,8] on Al surfaces, structure a is assigned to electron emission from decay of multipole surface plasmons, while bulk plasmon excitation appears at higher impact energy as shown in Fig. 2. The transition from multipole to bulk plasmon excitation is shown in Fig. 2 Panels (a) (d) of Fig. 2 report the plasmon dips observed in the derivative of the spectra revealed at growing incident ion energies. At 26 ev incident energy, the plasmon shoulder results in a minimum in the derivative at E m 6:2 ev, i.e..9 ev less than the energy of the q ¼ bulk plasmon structure appearing in the Fig. 2. (a d) Derivative dnðeþ=de showing the transition from multipole surface plasmon (msp) to bulk plasmon (BP) excitation. The vertical lines mark approximately the position of the multipole and of the bulk plasmon. The lines drawn through points indicate the polynomial secondary electrons background; (e h) Gaussian curve fits of the negative peaks obtained after background subtraction. electron excited spectrum [1]. This energy value is consistent with the attribution to electron emission from decay of multipole surface plasmons excited at or above the surface by potential energy transfer upon neutralization of incoming ions. At an incident energy of 4.5 kev, the plasmon structure appears at an energy that is consistent with that of the Mg bulk plasmon. The spectra acquired at intermediate energies show the transition

4 342 P. Riccardi et al. / Nucl. Instr. and Meth. in Phys. Res. B 212 (23) from surface to bulk plasmon excitation. As the energy of the incident ion is increased, we notice in Fig. 2 that the structure due to bulk plasmon decay grows on the high-energy side of the surface plasmon decay structure. 4 3 A BP A SP 4. Discussion The task of obtaining information about the electron yields for plasmon decay is rather difficult due to the overlap of structures arising from several processes. Several procedures have been applied [15,16] to disentangle the plasmon structure from the background due to other electron emission phenomena. Fig. 2 illustrates the application of one this procedure [16], based on the analysis of the derivative of the spectra, to the case of electron emission by He þ ion impact on Mg surfaces. Panels (a) (d) of Fig. 2 report examples of background subtraction from the derivative of the spectra. The background curve was obtained by fitting two regions on both side of the plasmon structure with a polynomial function. Panels (e) (h) report the negative peaks obtained after the subtraction. We observe that at 46 ev incident energy the structure is well reproduced by a Gaussian curve centered at an energy below that corresponding to a bulk plasmon decay structure and assigned to decay of multipole surface plasmons. At higher incident energies, the structure is not reproduced by only one curve, but by the superposition of two Gaussians of constant width and position corresponding to the surface and the bulk plasmon features. The areas A SP and A BP of these Gaussians are shown as a function of incident ion energy in the upper panel of Fig. 3. Also shown in the lower panel of Fig. 3 is the ratio R ¼ A BP =c tot. The analysis shown in Figs. 2 and 3 compares well with similar results obtained in the case of experiments of Ne þ ion impact on Al surfaces [8], showing that the procedure gives valuable insight into the mechanisms for plasmon production in free electron metals by slow ions. In [16], it has been discussed that absolute electron yields from surface and bulk plasmon decay could be obtained by multiplying by a factor C ¼ 2E F =3 the areas of A(1 e/ev) R=A BP /γ tot (1 /ev) Incident energy (kev) Fig. 3. Top: Areas of the surface (A SP ) and bulk plasmon (A BP ) Gaussians described in Fig. 2 versus He þ incident energy. The lines through data points are used to guide the eye. Bottom: ratio R ¼ A BP =c tot versus incident He þ energy. the corresponding Gaussians in Fig. 2. However, we find that this value of the factor C is a good approximation only for very narrow plasmon width, while for plasmon structure whose width is about 2 ev, like in Mg and Al, this value is underestimated by about 4%. Furthermore, as will be shown later in this section, the particular choice of the background curve affects the areas of the plasmon structure in the derivative resulting in a further strong underestimation. Therefore, to study the relative contribution to electron emission from plasmon decay and neutralization via Auger

5 P. Riccardi et al. / Nucl. Instr. and Meth. in Phys. Res. B 212 (23) processes, we adopted the procedure shown in Fig. 3. The energy distribution N ðeþ of emitted electrons can be written as NðEÞ ¼T ðeþn ðeþ, where N ðeþ is the internal energy distribution, i.e. the spectrum of electrons excited in the solid at energy E above the vacuum level and T ðeþ is the surface transmission function, giving the probability for an electron of excitation energy E to be transmitted through the surface. As shown in Fig. 1, electron cascade, plasmon decay and Auger electrons contribute to NðEÞ. Thus, we have N ðeþ ¼ N K ðeþþn p ðeþþn A ðeþ, where N K, N p, N A are the internal energy distribution of electrons excited respectively by the three processes. In the case of experiments on Mg samples, the three emission mechanisms are well separated in energy. Fig. 4 shows the attempt to reproduce the experimental spectrum NðEÞ of electrons emitted by 46 ev He þ ion impact by modeling the three internal distributions in the very simplest fashion and by using a suitable choice for T ðeþ as Eq. (16) in [4]. As in [16], for N p we considered the convolution of a parabolic density of states with a Lorentzian. We found that a width C pl 1:7 ev, which is consistent with the width of the plasmon structures we observed in electron energy loss experiments, yielded a good reproduction of the experimental spectrum. The other adjustable parameter in N p is E m, the high-energy edge of the plasmon decay structure. The value of E m we found agrees with the expectation of multipole plasmon decay (the multipole plasmon energy is.9e vp, where E vp is the q ¼ bulk plasmon energy). For N A we considered the self-convolution of a parabolic density of states to represent Auger transitions involving two electrons in the Mg conduction band and a hole in the incoming ion. A Lorentzian broadening of a.5 ev was introduced in the convolution and the energy released in neutralization, E n, was varied to reproduce the position of the structure, thus taking into account the image energy shift. This simple model can reproduce the Auger structure well, except for the high-energy tail. However, this discrepancy does not introduce a significant error in the estimation N(e) (e/ev) dn/de (1 e/ev 2 ) N k N p 46 ev of the area of the structure, and is therefore neglected here to keep the description on the simplest grounds. For N k ðeþ, we found that a simple exponential function of the type a be yielded a good reproduction of the cascade peak. Fig. 4 shows that the experimental spectrum can be reproduced satisfactorily, allowing the estimation of the relative contribution to electron emission due to plasmon decay and Auger neutralization, i.e. the ratios R SP ¼ c SP =c tot and R A ¼ c A =c tot, where c SP and c A are the electron yields for the two process respectively. We find R SP ¼ :25 and R A ¼ :15. The uncertainties in these values are estimated to be about 15% by varying the relative weight of the N A Kinetic Energy (ev) Fig. 4. Top: The energy spectrum of electrons ejected from Mg by 46 He þ ev ions is reproduced by the sum of three contributions: collision cascade (N k ), plasmon decay (N p ) and Auger neutralization (N AN ). Bottom: Derivative of the experimental and the calculated spectra.

6 344 P. Riccardi et al. / Nucl. Instr. and Meth. in Phys. Res. B 212 (23) three calculated energy distributions in the reproduction of the experimental spectrum and also by using other functional forms for N k ðeþ, as well as for the surface transmission function T ðeþ. To further check the reliability of the analysis, the lower panel of Fig. 4 shows that the procedure gives also a good reproduction of the derivative of the experimental spectrum, where the plasmon feature is clearer. This observation confirms that the plasmon excitation is needed to explain the data and that its contribution to the electron emission spectrum is properly estimated. It is interesting to notice that the background given by the derivative of the cascade peak is significantly different from that shown in Fig. 2. Subtraction of this background from the derivative of the experimental spectrum results in the negative peak shown in Fig. 5, which has an area about twice larger than the subtracted peak shown in panel (e) of Fig. 2. The subtracted structure in Fig. 4 shows the Lorentzian broadening due to finite plasmon lifetime, but it is also fairly well dn/de (1 e/ev 2 ) Energy (ev) Subtracted plasmon dip Lorentzian Gaussian Fig. 5. Lorentzian and Gaussian fit of the negative plasmon dip resulting after subtraction from the derivative of the experimental spectrum of the background given by the derivative of the cascade peak shown in Fig. 3. reproduced by a Gaussian distribution, thus justifying the use of Gaussian curves so far adopted in Fig. 2 and in the literature [8,16]. The different tailing of the two distributions is masked when the background shown in Fig. 2 is subtracted from the experimental data. In conclusion, the results presented in this work are consistent with the physical picture depicted in previous studies of plasmon excitation in free electron metals by slow ions. Low momentum bulk plasmons are observed for incident energies in the kinetic electron emission regime [4], in which electron excitation is mostly determined by the transfer of the kinetic energy of the projectile. At lower energies, where electron emission is mainly determined by the transfer of the potential energy released when incoming ions neutralize, we observe the excitation of multipole surface plasmons. We have shown that existing methods of analysis of the derivatives of the experimental spectra give valuable insight into the mechanisms for plasmon excitation by slow ions, but require particular care in the attempt of extracting yields of electron emission from plasmon decay. Therefore, we applied a different procedure based on the analysis of the spectra. Our admittedly simplified data analysis cannot fully account for the wealth of information contained in the spectra, which call for theoretical investigation. Nevertheless, it strongly supports the important conclusion that electron emission from plasmon decay is more intense than that from Auger neutralization. This results is in contrast with recent works [1 12], were plasmon excitation and decay was discussed as a minor contribution to potential electron emission from Al surfaces under ion irradiation [1 12], and confirms the importance of potential plasmon excitation in ion neutralization at free electron metal surfaces. References [1] R.A. Baragiola, C.A. Dukes, P. Riccardi, Nucl. Instr. and Meth. B 182 (21) 73. [2] M.S. Chung, T.E. Everhart, Phys. Rev. B 15 (1977) 4699.

7 P. Riccardi et al. / Nucl. Instr. and Meth. in Phys. Res. B 212 (23) [3] H.D. Hagstrum, in: N.H. Tolk, J.C. Tully, W. Heiland, C.W. White (Eds.), Inelastic Ion-Surface Collisions, Academic Press, NY, 1977, p. 1. [4] R.A. Baragiola, in: J.W. Rabalais (Ed.), Low Energy Ion-Surface Interaction, Wiley, New York, 1994, Chapter 4. [5] R.A. Baragiola, C.A. Dukes, Phys. Rev. Lett. 76 (1996) 14. [6] R. Monreal, Surf. Sci. 388 (1997) 231. [7] P. Riccardi, P. Barone, A. Bonanno, A. Oliva, R.A. Baragiola, Phys. Rev. Lett. 84 (2) 378. [8] P. Barone, R.A. Baragiola, A. Bonanno, M. Camarca, A. Oliva, P. Riccardi, F. Xu, Surf. Sci. 48 (21) L42. [9] K.D. Tsuei, E.W. Plummer, A. Liebsch, E. Pelke, K. Kempa, P. Bakshi, Surf. Sci. 247 (1991) 32. [1] B. Van Someren, P.A. Zeijlmans van Emmichoven, A. Niehaus, Phys. Rev. A 61 (2) [11] HP. Winter, H. Eder, F. Aumayr, J. Lorincik, Z. Sroubek, Nucl. Instr. and Meth. B 182 (21) 15. [12] J.C. Lancaster, F.J. Kontur, P. Nordlander, G.K. Walters, F.B. Dunning, Nucl. Instr. and Meth. B 193 (22) 656. [13] H.D. Hagstrum, Y. Takeishi, D.D. Pretzer, Phys. Rev. 139A (1965) 526. [14] R. Monreal, S.P. Apell, Nucl. Instr. and Meth. B 83 (1993) 459. [15] S.M. Ritzau, R.A. Baragiola, R.C. Monreal, Phys. Rev. B 59 (1999) [16] N. Stolterfoht, D. Niemann, V. Hoffmann, M. R osler, R.A. Baragiola, Phys. Rev. B 41 (2) 5292.

The excitation of collective electronic modes in Al by slow single charged Ne ions

The excitation of collective electronic modes in Al by slow single charged Ne ions Surface Science 480 2001) L420±L426 Surface Science Letters www.elsevier.nl/locate/susc The excitation of collective electronic modes in Al by slow single charged Ne ions P. Barone a, R.A. Baragiola b,

More information

Mechanisms for ion-induced plasmon excitation in metals

Mechanisms for ion-induced plasmon excitation in metals Nuclear Instruments and Methods in Physics Research B 157 (1999) 110±115 www.elsevier.nl/locate/nimb Mechanisms for ion-induced plasmon excitation in metals R.A. Baragiola a, *, S.M. Ritzau a, R.C. Monreal

More information

Plasmon production by the decay of hollow Ne atoms near an Al surface

Plasmon production by the decay of hollow Ne atoms near an Al surface PHYSICAL REVIEW A, VOLUME 61, 052902 Plasmon production by the decay of hollow Ne atoms near an Al surface N. Stolterfoht, D. Niemann, V. Hoffmann, M. Rösler, and R. A. Baragiola* Hahn-Meitner-Institut

More information

Electron Emission from Surfaces Mediated by Ion-Induced Plasmon Excitation

Electron Emission from Surfaces Mediated by Ion-Induced Plasmon Excitation 6 Electron Emission from Surfaces Mediated by Ion-Induced Plasmon Excitation Raúl A. Baragiola and R. Carmina Monreal We review theoretical and experimental research on electron emission due to plasmon

More information

Many-body shake-up in Auger neutralization of slow Ar + ions at Al surfaces

Many-body shake-up in Auger neutralization of slow Ar + ions at Al surfaces PHYSICAL REVIEW A 7, 052903 2005 Many-body shae-up in Auger neutralization of slow Ar + ions at Al surfaces A. Sindona, R. A. Baragiola, 2 G. Falcone, A. Oliva, and P. Riccardi,2, * Dipartimento di Fisica,

More information

Lecture 5. X-ray Photoemission Spectroscopy (XPS)

Lecture 5. X-ray Photoemission Spectroscopy (XPS) Lecture 5 X-ray Photoemission Spectroscopy (XPS) 5. Photoemission Spectroscopy (XPS) 5. Principles 5.2 Interpretation 5.3 Instrumentation 5.4 XPS vs UV Photoelectron Spectroscopy (UPS) 5.5 Auger Electron

More information

This article was originally published in a journal published by Elsevier, and the attached copy is provided by Elsevier for the author s benefit and for the benefit of the author s institution, for non-commercial

More information

Electrostatic charging e ects in fast H interactions with thin Ar

Electrostatic charging e ects in fast H interactions with thin Ar Nuclear Instruments and Methods in Physics Research B 157 (1999) 116±120 www.elsevier.nl/locate/nimb Electrostatic charging e ects in fast H interactions with thin Ar lms D.E. Grosjean a, R.A. Baragiola

More information

Auger electron emission from metals induced by low energy ion bombardment: Effect of the band structure and Fermi edge singularity

Auger electron emission from metals induced by low energy ion bombardment: Effect of the band structure and Fermi edge singularity Surface Science 601 (2007) 1205 1211 www.elsevier.com/locate/susc Auger electron emission from metals induced by low energy ion bombardment: Effect of the band structure and Fermi edge singularity A. Sindona

More information

Keywords: electron spectroscopy, coincidence spectroscopy, Auger photoelectron, background elimination, Low Energy Tail (LET)

Keywords: electron spectroscopy, coincidence spectroscopy, Auger photoelectron, background elimination, Low Energy Tail (LET) Measurement of the background in Auger-photoemission coincidence spectra (APECS) associated with inelastic or multi-electron valence band photoemission processes S. Satyal 1, P.V. Joglekar 1, K. Shastry

More information

Spin-polarized electron emission spectroscopy (SPEES) at Nif 110) and PtMnSb surfaces *

Spin-polarized electron emission spectroscopy (SPEES) at Nif 110) and PtMnSb surfaces * 342 Nuclear nstruments and Methods in Physics Research B58 (1991) 342-346 North-Holland Spin-polarized electron emission spectroscopy (SPEES) at Nif 110) and PtMnSb surfaces * K. Waters, M. Lu and C. Rau

More information

Electron momentum spectroscopy of metals

Electron momentum spectroscopy of metals Electron momentum spectroscopy of metals M. Vos, A.S. Kheifets and E. Weigold Atomic and Molecular Physics Laboratories, Research School of Physical Sciences and Engineering, Australian, National University

More information

5.8 Auger Electron Spectroscopy (AES)

5.8 Auger Electron Spectroscopy (AES) 5.8 Auger Electron Spectroscopy (AES) 5.8.1 The Auger Process X-ray and high energy electron bombardment of atom can create core hole Core hole will eventually decay via either (i) photon emission (x-ray

More information

X-Ray Photoelectron Spectroscopy (XPS)-2

X-Ray Photoelectron Spectroscopy (XPS)-2 X-Ray Photoelectron Spectroscopy (XPS)-2 Louis Scudiero http://www.wsu.edu/~scudiero; 5-2669 Fulmer 261A Electron Spectroscopy for Chemical Analysis (ESCA) The 3 step model: 1.Optical excitation 2.Transport

More information

Electronic excitation in atomic collision cascades

Electronic excitation in atomic collision cascades Nuclear Instruments and Methods in Physics Research B 8 (5) 35 39 www.elsevier.com/locate/nimb Electronic excitation in atomic collision cascades A. Duvenbeck a, Z. Sroubek b, A. Wucher a, * a Department

More information

A.5. Ion-Surface Interactions A.5.1. Energy and Charge Dependence of the Sputtering Induced by Highly Charged Xe Ions T. Sekioka,* M. Terasawa,* T.

A.5. Ion-Surface Interactions A.5.1. Energy and Charge Dependence of the Sputtering Induced by Highly Charged Xe Ions T. Sekioka,* M. Terasawa,* T. A.5. Ion-Surface Interactions A.5.1. Energy and Charge Dependence of the Sputtering Induced by Highly Charged Xe Ions T. Sekioka,* M. Terasawa,* T. Mitamura,* M.P. Stöckli, U. Lehnert, and D. Fry The interaction

More information

Advanced Lab Course. X-Ray Photoelectron Spectroscopy 1 INTRODUCTION 1 2 BASICS 1 3 EXPERIMENT Qualitative analysis Chemical Shifts 7

Advanced Lab Course. X-Ray Photoelectron Spectroscopy 1 INTRODUCTION 1 2 BASICS 1 3 EXPERIMENT Qualitative analysis Chemical Shifts 7 Advanced Lab Course X-Ray Photoelectron Spectroscopy M210 As of: 2015-04-01 Aim: Chemical analysis of surfaces. Content 1 INTRODUCTION 1 2 BASICS 1 3 EXPERIMENT 3 3.1 Qualitative analysis 6 3.2 Chemical

More information

The role of electronic friction of low-energy recoils in atomic collision cascades

The role of electronic friction of low-energy recoils in atomic collision cascades The role of electronic friction of low-energy recoils in atomic collision cascades A. Duvenbeck 1 and O. Weingart 2 and V. Buss 2 and A. Wucher 1 1 Department of Physics, University of Duisburg-Essen,

More information

Appearance Potential Spectroscopy

Appearance Potential Spectroscopy Appearance Potential Spectroscopy Submitted by Sajanlal P. R CY06D009 Sreeprasad T. S CY06D008 Dept. of Chemistry IIT MADRAS February 2006 1 Contents Page number 1. Introduction 3 2. Theory of APS 3 3.

More information

4. Inelastic Scattering

4. Inelastic Scattering 1 4. Inelastic Scattering Some inelastic scattering processes A vast range of inelastic scattering processes can occur during illumination of a specimen with a highenergy electron beam. In principle, many

More information

Nonstatistical fluctuations for deep inelastic processes

Nonstatistical fluctuations for deep inelastic processes Nonstatistical fluctuations for deep inelastic processes in 27 Al + 27 Al collision Introduction Experimental procedures Cross section excitation functions (EFs) 1. Statistical analysis (a) Energy autocorrelation

More information

IV. Surface analysis for chemical state, chemical composition

IV. Surface analysis for chemical state, chemical composition IV. Surface analysis for chemical state, chemical composition Probe beam Detect XPS Photon (X-ray) Photoelectron(core level electron) UPS Photon (UV) Photoelectron(valence level electron) AES electron

More information

Electron emission from low-energy Xe + ions interacting with a MgO thin film deposited on a Mo substrate

Electron emission from low-energy Xe + ions interacting with a MgO thin film deposited on a Mo substrate PHYSICAL REVIEW B 69, 245414 (2004) Electron emission from low-energy Xe + ions interacting with a MgO thin film deposited on a Mo substrate Y. T. Matulevich and P. A. Zeijlmans van Emmichoven Debye Institute,

More information

X-Ray Photoelectron Spectroscopy (XPS)-2

X-Ray Photoelectron Spectroscopy (XPS)-2 X-Ray Photoelectron Spectroscopy (XPS)-2 Louis Scudiero http://www.wsu.edu/~pchemlab ; 5-2669 Fulmer 261A Electron Spectroscopy for Chemical Analysis (ESCA) The 3 step model: 1.Optical excitation 2.Transport

More information

Electron Spectroscopy

Electron Spectroscopy Electron Spectroscopy Photoelectron spectroscopy is based upon a single photon in/electron out process. The energy of a photon is given by the Einstein relation : E = h ν where h - Planck constant ( 6.62

More information

Depth Distribution Functions of Secondary Electron Production and Emission

Depth Distribution Functions of Secondary Electron Production and Emission Depth Distribution Functions of Secondary Electron Production and Emission Z.J. Ding*, Y.G. Li, R.G. Zeng, S.F. Mao, P. Zhang and Z.M. Zhang Hefei National Laboratory for Physical Sciences at Microscale

More information

Lecture 17 Auger Electron Spectroscopy

Lecture 17 Auger Electron Spectroscopy Lecture 17 Auger Electron Spectroscopy Auger history cloud chamber Although Auger emission is intense, it was not used until 1950 s. Evolution of vacuum technology and the application of Auger Spectroscopy

More information

Target material dependence of secondary electron images induced by focused ion beams

Target material dependence of secondary electron images induced by focused ion beams Surface and Coatings Technology 158 159 (00) 8 13 Target material dependence of secondary electron images induced by focused ion beams a, b K. Ohya *, T. Ishitani a Faculty of Engineering, The University

More information

The use of MIM tunnel junctions to investigate kinetic electron excitation in atomic collision cascades

The use of MIM tunnel junctions to investigate kinetic electron excitation in atomic collision cascades Nuclear Instruments and Methods in Physics Research B 230 (2005) 608 612 www.elsevier.com/locate/nimb The use of MIM tunnel junctions to investigate kinetic electron excitation in atomic collision cascades

More information

PROTON-PROTON FEMTOSCOPY AND ACCESS TO DYNAMICAL SOURCES AT INTERMEDIATE ENERGIES

PROTON-PROTON FEMTOSCOPY AND ACCESS TO DYNAMICAL SOURCES AT INTERMEDIATE ENERGIES EPJ Web of Conferences 66, 03068 (2014) DOI: 10.1051/ epjconf/ 2014 6603068 C Owned by the authors, published by EDP Sciences, 2014 PROTON-PROTON FEMTOSCOPY AND ACCESS TO DYNAMICAL SOURCES AT INTERMEDIATE

More information

A comparison of molecular dynamic simulations and experimental observations: the sputtering of gold {1 0 0} by 20 kev argon

A comparison of molecular dynamic simulations and experimental observations: the sputtering of gold {1 0 0} by 20 kev argon Applied Surface Science 231 232 (2004) 39 43 A comparison of molecular dynamic simulations and experimental observations: the sputtering of gold {1 0 0} by 20 kev argon C.M. McQuaw *, E.J. Smiley, B.J.

More information

Inelastic soft x-ray scattering, fluorescence and elastic radiation

Inelastic soft x-ray scattering, fluorescence and elastic radiation Inelastic soft x-ray scattering, fluorescence and elastic radiation What happens to the emission (or fluorescence) when the energy of the exciting photons changes? The emission spectra (can) change. One

More information

arxiv: v1 [astro-ph] 30 Jul 2008

arxiv: v1 [astro-ph] 30 Jul 2008 arxiv:0807.4824v1 [astro-ph] 30 Jul 2008 THE AIR-FLUORESCENCE YIELD F. Arqueros, F. Blanco, D. Garcia-Pinto, M. Ortiz and J. Rosado Departmento de Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias

More information

Auger Electron Spectrometry. EMSE-515 F. Ernst

Auger Electron Spectrometry. EMSE-515 F. Ernst Auger Electron Spectrometry EMSE-515 F. Ernst 1 Principle of AES electron or photon in, electron out radiation-less transition Auger electron electron energy properties of atom 2 Brief History of Auger

More information

Experimental X-Ray Spectroscopy: Part 2

Experimental X-Ray Spectroscopy: Part 2 Experimental X-Ray Spectroscopy: Part 2 We will use the skills you have learned this week to analyze this spectrum: What are the spectral lines? Can we determine the plasma temperature and density? Other

More information

Auger Electron Spectroscopy (AES) Prof. Paul K. Chu

Auger Electron Spectroscopy (AES) Prof. Paul K. Chu Auger Electron Spectroscopy (AES) Prof. Paul K. Chu Auger Electron Spectroscopy Introduction Principles Instrumentation Qualitative analysis Quantitative analysis Depth profiling Mapping Examples The Auger

More information

Lecture 20 Auger Electron Spectroscopy

Lecture 20 Auger Electron Spectroscopy Lecture 20 Auger Electron Spectroscopy Auger history cloud chamber Although Auger emission is intense, it was not used until 1950 s. Evolution of vacuum technology and the application of Auger Spectroscopy

More information

Nuclear Cross-Section Measurements at the Manuel Lujan Jr. Neutron Scattering Center

Nuclear Cross-Section Measurements at the Manuel Lujan Jr. Neutron Scattering Center 1 Nuclear Cross-Section Measurements at the Manuel Lujan Jr. Neutron Scattering Center M. Mocko 1, G. Muhrer 1, F. Tovesson 1, J. Ullmann 1 1 LANSCE, Los Alamos National Laboratory, Los Alamos NM 87545,

More information

SUPPLEMENTARY INFORMATION

SUPPLEMENTARY INFORMATION doi: 10.1038/nature06219 SUPPLEMENTARY INFORMATION Abrupt Onset of Second Energy Gap at Superconducting Transition of Underdoped Bi2212 Wei-Sheng Lee 1, I. M. Vishik 1, K. Tanaka 1,2, D. H. Lu 1, T. Sasagawa

More information

DEVELOPMENT OF A NEW POSITRON LIFETIME SPECTROSCOPY TECHNIQUE FOR DEFECT CHARACTERIZATION IN THICK MATERIALS

DEVELOPMENT OF A NEW POSITRON LIFETIME SPECTROSCOPY TECHNIQUE FOR DEFECT CHARACTERIZATION IN THICK MATERIALS Copyright JCPDS - International Centre for Diffraction Data 2004, Advances in X-ray Analysis, Volume 47. 59 DEVELOPMENT OF A NEW POSITRON LIFETIME SPECTROSCOPY TECHNIQUE FOR DEFECT CHARACTERIZATION IN

More information

Nuclear Instruments and Methods in Physics Research B

Nuclear Instruments and Methods in Physics Research B Nuclear Instruments and Methods in Physics Research B 315 (2013) 206 212 Contents lists available at SciVerse ScienceDirect Nuclear Instruments and Methods in Physics Research B journal homepage: www.elsevier.com/locate/nimb

More information

The rotational γ -continuum in the mass region A 110

The rotational γ -continuum in the mass region A 110 Nuclear Physics A 673 (2000) 64 84 www.elsevier.nl/locate/npe The rotational γ -continuum in the mass region A 110 A. Bracco a, S. Frattini a,s.leoni a, F. Camera a, B. Million a,n.blasi a, G. Falconi

More information

Coincidence measurements of highly charged ions interacting with a clean Au 111 surface

Coincidence measurements of highly charged ions interacting with a clean Au 111 surface Coincidence measurements of highly charged ions interacting with a clean Au 111 surface C. Lemell, 1,2, * J. Stöckl, 1 J. Burgdörfer, 2 G. Betz, 1 HP. Winter, 1 and F. Aumayr 1 1 Institut für Allgemeine

More information

RESEARCH REPOSITORY.

RESEARCH REPOSITORY. RESEARCH REPOSITORY This is the author s final version of the work, as accepted for publication following peer review but without the publisher s layout or pagination. The definitive version is available

More information

4. How can fragmentation be useful in identifying compounds? Permits identification of branching not observed in soft ionization.

4. How can fragmentation be useful in identifying compounds? Permits identification of branching not observed in soft ionization. Homework 9: Chapters 20-21 Assigned 12 April; Due 17 April 2006; Quiz on 19 April 2006 Chap. 20 (Molecular Mass Spectroscopy) Chap. 21 (Surface Analysis) 1. What are the types of ion sources in molecular

More information

Fig 1: Auger Electron Generation (a) Step 1 and (b) Step 2

Fig 1: Auger Electron Generation (a) Step 1 and (b) Step 2 Auger Electron Spectroscopy (AES) Physics of AES: Auger Electrons were discovered in 1925 but were used in surface analysis technique in 1968. Auger Electron Spectroscopy (AES) is a very effective method

More information

Photoelectron Peak Intensities in Solids

Photoelectron Peak Intensities in Solids Photoelectron Peak Intensities in Solids Electronic structure of solids Photoelectron emission through solid Inelastic scattering Other excitations Intrinsic and extrinsic Shake-up, shake-down and shake-off

More information

QUESTIONS AND ANSWERS

QUESTIONS AND ANSWERS QUESTIONS AND ANSWERS (1) For a ground - state neutral atom with 13 protons, describe (a) Which element this is (b) The quantum numbers, n, and l of the inner two core electrons (c) The stationary state

More information

Electron Rutherford Backscattering, a versatile tool for the study of thin films

Electron Rutherford Backscattering, a versatile tool for the study of thin films Electron Rutherford Backscattering, a versatile tool for the study of thin films Maarten Vos Research School of Physics and Engineering Australian National University Canberra Australia Acknowledgements:

More information

Charge transfer and memory loss in kev oxygen-ion scattering from Cu 001

Charge transfer and memory loss in kev oxygen-ion scattering from Cu 001 PHYSICAL REVIEW B VOLUME 61, NUMBER 3 15 JANUARY 2000-I Charge transfer and memory loss in kev oxygen-ion scattering from Cu 001 A. C. Lavery, C. E. Sosolik, C. A. Keller, and B. H. Cooper* Laboratory

More information

Ion sputtering yield coefficients from In thin films bombarded by different energy Ar + ions

Ion sputtering yield coefficients from In thin films bombarded by different energy Ar + ions Ion sputtering yield coefficients from thin films bombarded by different energy Ar + ions MJ Madito, H Swart and JJ Terblans 1 Department of Physics, University of the Free State, P.. Box 339, Bloemfontein,

More information

Monte Carlo study of medium-energy electron penetration in aluminium and silver

Monte Carlo study of medium-energy electron penetration in aluminium and silver NUKLEONIKA 015;60():361366 doi: 10.1515/nuka-015-0035 ORIGINAL PAPER Monte Carlo study of medium-energy electron penetration in aluminium and silver Asuman Aydın, Ali Peker Abstract. Monte Carlo simulations

More information

Plasma Radiation. Ø Free electrons Blackbody emission Bremsstrahlung

Plasma Radiation. Ø Free electrons Blackbody emission Bremsstrahlung Plasma Radiation Ø Free electrons Blackbody emission Bremsstrahlung Ø Bound electrons (Z>2) Unresolved, multi-line emission Resolved line emission -- Single Z +n Objective Infer a thermodynamic quantity

More information

Neutron Interactions Part I. Rebecca M. Howell, Ph.D. Radiation Physics Y2.5321

Neutron Interactions Part I. Rebecca M. Howell, Ph.D. Radiation Physics Y2.5321 Neutron Interactions Part I Rebecca M. Howell, Ph.D. Radiation Physics rhowell@mdanderson.org Y2.5321 Why do we as Medical Physicists care about neutrons? Neutrons in Radiation Therapy Neutron Therapy

More information

X-Ray Photoelectron Spectroscopy (XPS)

X-Ray Photoelectron Spectroscopy (XPS) X-Ray Photoelectron Spectroscopy (XPS) Louis Scudiero http://www.wsu.edu/~scudiero; 5-2669 Fulmer 261A Electron Spectroscopy for Chemical Analysis (ESCA) The basic principle of the photoelectric effect

More information

The Franck-Hertz Experiment Physics 2150 Experiment No. 9 University of Colorado

The Franck-Hertz Experiment Physics 2150 Experiment No. 9 University of Colorado Experiment 9 1 Introduction The Franck-Hertz Experiment Physics 2150 Experiment No. 9 University of Colorado During the late nineteenth century, a great deal of evidence accumulated indicating that radiation

More information

Angular dependence of the sputtering yield of water ice by 100 kev proton bombardment

Angular dependence of the sputtering yield of water ice by 100 kev proton bombardment Surface Science 588 (2005) 1 5 www.elsevier.com/locate/susc Angular dependence of the sputtering yield of water ice by 100 kev proton bombardment R.A. Vidal *, B.D. Teolis, R.A. Baragiola Laboratory for

More information

Ion-induced kinetic electron emission from HOPG with different surface orientation

Ion-induced kinetic electron emission from HOPG with different surface orientation EUROPHYSICS LETTERS 15 June 2005 Europhys. Lett., 70 (6), pp. 768 774 (2005) DOI: 10.1209/epl/i2004-10521-x Ion-induced kinetic electron emission from HOPG with different surface orientation S. Cernusca,

More information

Characterization of quasi-projectiles produced in symmetric collisions studied with INDRA Comparison with models

Characterization of quasi-projectiles produced in symmetric collisions studied with INDRA Comparison with models EPJ Web of Conferences 31, 00007 (2012) DOI: 10.1051/ epjconf/ 20123100007 C Owned by the authors, published by EDP Sciences - SIF, 2012 Characterization of quasi-projectiles produced in symmetric collisions

More information

Transit time broadening contribution to the linear evanescent susceptibility

Transit time broadening contribution to the linear evanescent susceptibility Supplementary note 1 Transit time broadening contribution to the linear evanescent susceptibility In this section we analyze numerically the susceptibility of atoms subjected to an evanescent field for

More information

Photon Interaction. Spectroscopy

Photon Interaction. Spectroscopy Photon Interaction Incident photon interacts with electrons Core and Valence Cross Sections Photon is Adsorbed Elastic Scattered Inelastic Scattered Electron is Emitted Excitated Dexcitated Stöhr, NEXAPS

More information

Stopping power for MeV 12 C ions in solids

Stopping power for MeV 12 C ions in solids Nuclear Instruments and Methods in Physics Research B 35 (998) 69±74 Stopping power for MeV C ions in solids Zheng Tao, Lu Xiting *, Zhai Yongjun, Xia Zonghuang, Shen Dingyu, Wang Xuemei, Zhao Qiang Department

More information

Institut für Experimentalphysik, Johannes Kepler Universität Linz, A-4040 Linz, Austria.

Institut für Experimentalphysik, Johannes Kepler Universität Linz, A-4040 Linz, Austria. On the Surface Sensitivity of Angular Scans in LEIS D. Primetzhofer a*, S.N. Markin a, R. Kolarova a, M. Draxler a R. Beikler b, E. Taglauer b and P. Bauer a a Institut für Experimentalphysik, Johannes

More information

MS482 Materials Characterization ( 재료분석 ) Lecture Note 2: UPS

MS482 Materials Characterization ( 재료분석 ) Lecture Note 2: UPS 2016 Fall Semester MS482 Materials Characterization ( 재료분석 ) Lecture Note 2: UPS Byungha Shin Dept. of MSE, KAIST 1 Course Information Syllabus 1. Overview of various characterization techniques (1 lecture)

More information

Ultraviolet Photoelectron Spectroscopy (UPS)

Ultraviolet Photoelectron Spectroscopy (UPS) Ultraviolet Photoelectron Spectroscopy (UPS) Louis Scudiero http://www.wsu.edu/~scudiero www.wsu.edu/~scudiero; ; 5-26695 scudiero@wsu.edu Photoemission from Valence Bands Photoelectron spectroscopy is

More information

X-ray photoelectron spectroscopic characterization of molybdenum nitride thin films

X-ray photoelectron spectroscopic characterization of molybdenum nitride thin films Korean J. Chem. Eng., 28(4), 1133-1138 (2011) DOI: 10.1007/s11814-011-0036-2 INVITED REVIEW PAPER X-ray photoelectron spectroscopic characterization of molybdenum nitride thin films Jeong-Gil Choi Department

More information

Two-photon Absorption Process in Semiconductor Quantum Dots

Two-photon Absorption Process in Semiconductor Quantum Dots Two-photon Absorption Process in Semiconductor Quantum Dots J. López Gondar 1, R. Cipolatti 1 and G. E. Marques 2. 1 Instituto de Matemática, Universidade Federal do Rio de Janeiro C.P. 68530, Rio de Janeiro,

More information

Copyright 2008, University of Chicago, Department of Physics. Experiment VI. Gamma Ray Spectroscopy

Copyright 2008, University of Chicago, Department of Physics. Experiment VI. Gamma Ray Spectroscopy Experiment VI Gamma Ray Spectroscopy 1. GAMMA RAY INTERACTIONS WITH MATTER In order for gammas to be detected, they must lose energy in the detector. Since gammas are electromagnetic radiation, we must

More information

Ted Madey s Scientific Career at NBS/NIST: Aspects of Auger Electron Spectroscopy (AES), X-ray Photoelectron Spectroscopy (XPS), and Vacuum Science

Ted Madey s Scientific Career at NBS/NIST: Aspects of Auger Electron Spectroscopy (AES), X-ray Photoelectron Spectroscopy (XPS), and Vacuum Science Ted Madey s Scientific Career at NBS/NIST: Aspects of Auger Electron Spectroscopy (AES), X-ray Photoelectron Spectroscopy (XPS), and Vacuum Science Cedric J. Powell 1. Ted s 25-year career at NBS/NIST:

More information

Molecular dynamics simulation of sputtering from a cylindrical track: EAM versus pair potentials

Molecular dynamics simulation of sputtering from a cylindrical track: EAM versus pair potentials Nuclear Instruments and Methods in Physics Research B 228 (5) 163 169 www.elsevier.com/locate/nimb Molecular dynamics simulation of sputtering from a cylindrical track: EAM versus pair potentials Orenthal

More information

Past searches for kev neutrinos in beta-ray spectra

Past searches for kev neutrinos in beta-ray spectra Past searches for kev neutrinos in beta-ray spectra Otokar Dragoun Nuclear Physics Institute of the ASCR Rez near Prague dragoun@ujf.cas.cz supported by GAČR, P203/12/1896 The ν-dark 2015 Workshop TUM

More information

Chemical Analysis in TEM: XEDS, EELS and EFTEM. HRTEM PhD course Lecture 5

Chemical Analysis in TEM: XEDS, EELS and EFTEM. HRTEM PhD course Lecture 5 Chemical Analysis in TEM: XEDS, EELS and EFTEM HRTEM PhD course Lecture 5 1 Part IV Subject Chapter Prio x-ray spectrometry 32 1 Spectra and mapping 33 2 Qualitative XEDS 34 1 Quantitative XEDS 35.1-35.4

More information

Auger decay of excited Ar projectiles emerging from carbon foils

Auger decay of excited Ar projectiles emerging from carbon foils J. Phys. B: Atom. Molec. Phys., Vol. 9, No. 15, 1976. Printed in Great Britain. @ 1976 LETTER TO THE EDITOR Auger decay of excited Ar projectiles emerging from carbon foils R A Baragiola?, P Ziem and N

More information

Hole-concentration dependence of band structure in (Bi,Pb) 2 (Sr,La) 2 CuO 6+δ determined by the angle-resolved photoemission spectroscopy

Hole-concentration dependence of band structure in (Bi,Pb) 2 (Sr,La) 2 CuO 6+δ determined by the angle-resolved photoemission spectroscopy Journal of Electron Spectroscopy and Related Phenomena 137 140 (2004) 663 668 Hole-concentration dependence of band structure in (Bi,Pb) 2 (Sr,La) 2 CuO 6+δ determined by the angle-resolved photoemission

More information

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution

More information

Physics 100 PIXE F06

Physics 100 PIXE F06 Introduction: Ion Target Interaction Elastic Atomic Collisions Very low energies, typically below a few kev Surface composition and structure Ion Scattering spectrometry (ISS) Inelastic Atomic Collisions

More information

Introduction to X-ray Photoelectron Spectroscopy (XPS) XPS which makes use of the photoelectric effect, was developed in the mid-1960

Introduction to X-ray Photoelectron Spectroscopy (XPS) XPS which makes use of the photoelectric effect, was developed in the mid-1960 Introduction to X-ray Photoelectron Spectroscopy (XPS) X-ray Photoelectron Spectroscopy (XPS), also known as Electron Spectroscopy for Chemical Analysis (ESCA) is a widely used technique to investigate

More information

Intensity / a.u. 2 theta / deg. MAPbI 3. 1:1 MaPbI 3-x. Cl x 3:1. Supplementary figures

Intensity / a.u. 2 theta / deg. MAPbI 3. 1:1 MaPbI 3-x. Cl x 3:1. Supplementary figures Intensity / a.u. Supplementary figures 110 MAPbI 3 1:1 MaPbI 3-x Cl x 3:1 220 330 0 10 15 20 25 30 35 40 45 2 theta / deg Supplementary Fig. 1 X-ray Diffraction (XRD) patterns of MAPbI3 and MAPbI 3-x Cl

More information

Evidence for partial dissociation of water on flat MgO(1 0 0) surfaces

Evidence for partial dissociation of water on flat MgO(1 0 0) surfaces 6 February 2002 Chemical Physics Letters 352 (2002) 318 322 www.elsevier.com/locate/cplett Evidence for partial dissociation of water on flat MgO(1 0 0) surfaces Y.D. Kim a, R.M. Lynden-Bell b, *, A. Alavi

More information

Development of new instrumentation for epithermal neutron scattering at very low angles

Development of new instrumentation for epithermal neutron scattering at very low angles Nuclear Instruments and Methods in Physics Research A 535 (2004) 121 125 www.elsevier.com/locate/nima Development of new instrumentation for epithermal neutron scattering at very low angles M. Tardocchi

More information

More Energetics of Alpha Decay The energy released in decay, Q, is determined by the difference in mass of the parent nucleus and the decay products, which include the daughter nucleus and the particle.

More information

A Comparison between Channel Selections in Heavy Ion Reactions

A Comparison between Channel Selections in Heavy Ion Reactions Brazilian Journal of Physics, vol. 39, no. 1, March, 2009 55 A Comparison between Channel Selections in Heavy Ion Reactions S. Mohammadi Physics Department, Payame Noor University, Mashad 91735, IRAN (Received

More information

A pattern recognition method for the RICH-based HMPID detector in ALICE

A pattern recognition method for the RICH-based HMPID detector in ALICE Nuclear Instruments and Methods in Physics Research A 433 (1999) 262}267 A pattern recognition method for the RICH-based HMPID detector in ALICE For the ALICE HMPID group and Collaboration D. Elia*, N.

More information

Beta Spectrum. T β,max = kev kev 2.5 ms. Eγ = kev

Beta Spectrum. T β,max = kev kev 2.5 ms. Eγ = kev HOM, 1/14/05; DVB 014-Jan-9, 01-Dec-17, 013-Oct-16 Beta Spectrum Goal: to investigate the spectrum of β rays emitted by a 137 Cs source. The instrument used is a so-called 180 o magnetic spectrometer that

More information

Electron Spettroscopies

Electron Spettroscopies Electron Spettroscopies Spettroscopy allows to characterize a material from the point of view of: chemical composition, electronic states and magnetism, electronic, roto-vibrational and magnetic excitations.

More information

Conversion Electron Spectroscopy in Transfermium Nuclei

Conversion Electron Spectroscopy in Transfermium Nuclei Conversion Electron Spectroscopy in Transfermium Nuclei R.-D. Herzberg University of iverpool, iverpool, 69 7ZE, UK Abstract Conversion electron spectroscopy is an essential tool for the spectroscopy of

More information

Thickness dependence of the surface plasmon dispersion in ultrathin aluminum films on silicon

Thickness dependence of the surface plasmon dispersion in ultrathin aluminum films on silicon Surface Science 600 (2006) 4966 4971 www.elsevier.com/locate/susc Thickness dependence of the surface plasmon dispersion in ultrathin aluminum films on silicon Yinghui Yu, Zhe Tang, Ying Jiang, Kehui Wu

More information

SUPPLEMENTARY INFORMATION

SUPPLEMENTARY INFORMATION doi:10.1038/nature10721 Experimental Methods The experiment was performed at the AMO scientific instrument 31 at the LCLS XFEL at the SLAC National Accelerator Laboratory. The nominal electron bunch charge

More information

ρ. Photoemission is presumed to occur if the photon energy is enough to raise qf πε, where q is the electron charge, F the electric field, and ε 0 φ ω

ρ. Photoemission is presumed to occur if the photon energy is enough to raise qf πε, where q is the electron charge, F the electric field, and ε 0 φ ω Pulsed photoelectric field emission from needle cathodes C. Hernandez Garcia and C. A. Brau Vanderbilt University, Department of Physics, Nashville, TN 37235, USA Experiments have been carried out to measure

More information

Spin-polarized e,2e) spectroscopy of ferromagnetic iron

Spin-polarized e,2e) spectroscopy of ferromagnetic iron Surface Science 482±485 2001) 1015±1020 www.elsevier.nl/locate/susc Spin-polarized e,2e) spectroscopy of ferromagnetic iron S. Samarin a, O. Artamonov b, J. Berakdar a, *, A. Morozov a,1, J. Kirschner

More information

E cient hydration of Cs ions scattered from ice lms

E cient hydration of Cs ions scattered from ice lms Nuclear Instruments and Methods in Physics Research B 157 (1999) 191±197 www.elsevier.nl/locate/nimb E cient hydration of Cs ions scattered from ice lms T.-H. Shin, S.-J. Han, H. Kang * Department of Chemistry

More information

8.6 Relaxation Processes

8.6 Relaxation Processes CHAPTER 8. INNER SHELLS 175 Figure 8.17: Splitting of the 3s state in Fe which is missing in Zn. Refs. [12,13]. be aligned parallel or antiparallel with the spins of the 3d electrons of iron. 13 Thus we

More information

Methods of surface analysis

Methods of surface analysis Methods of surface analysis Nanomaterials characterisation I RNDr. Věra Vodičková, PhD. Surface of solid matter: last monoatomic layer + absorbed monolayer physical properties are effected (crystal lattice

More information

Towards surface experiments at HITRAP

Towards surface experiments at HITRAP Towards surface experiments at HITRAP Erwin Bodewits, H. Bekker, A.J. de Nijs, D.Winklehner, B.Daniel, G. Kowarik, K. Dobes, F. Aumayr and Ronnie Hoekstra atomic physics HITRAP - GSI Introduction Facility

More information

Surface-plasmon-assisted secondary-electron emission from an atomically at LiF(001) surface

Surface-plasmon-assisted secondary-electron emission from an atomically at LiF(001) surface Nuclear Instruments and Methods in Physics Research B 164±165 (2000) 933±937 www.elsevier.nl/locate/nimb Surface-plasmon-assisted secondary-electron emission from an atomically at LiF(001) surface Kenji

More information

high temp ( K) Chapter 20: Atomic Spectroscopy

high temp ( K) Chapter 20: Atomic Spectroscopy high temp (2000-6000K) Chapter 20: Atomic Spectroscopy 20-1. An Overview Most compounds Atoms in gas phase high temp (2000-6000K) (AES) (AAS) (AFS) sample Mass-to-charge (ICP-MS) Atomic Absorption experiment

More information

Desorption and Sputtering on Solid Surfaces by Low-energy Multicharged Ions

Desorption and Sputtering on Solid Surfaces by Low-energy Multicharged Ions Desorption and Sputtering on Solid Surfaces by Low-energy Multicharged Ions K. Motohashi Department of Biomedical Engineering, Toyo University motohashi@toyonet.toyo.ac.jp 1. Background Sputtering and

More information

Nuclear cross-section measurements at the Manuel Lujan Jr. Neutron Scattering Center. Michal Mocko

Nuclear cross-section measurements at the Manuel Lujan Jr. Neutron Scattering Center. Michal Mocko Nuclear cross-section measurements at the Manuel Lujan Jr. Neutron Scattering Center Michal Mocko G. Muhrer, F. Tovesson, J. Ullmann International Topical Meeting on Nuclear Research Applications and Utilization

More information

ELECTRIC FIELD INFLUENCE ON EMISSION OF CHARACTERISTIC X-RAY FROM Al 2 O 3 TARGETS BOMBARDED BY SLOW Xe + IONS

ELECTRIC FIELD INFLUENCE ON EMISSION OF CHARACTERISTIC X-RAY FROM Al 2 O 3 TARGETS BOMBARDED BY SLOW Xe + IONS 390 ELECTRIC FIELD INFLUENCE ON EMISSION OF CHARACTERISTIC X-RAY FROM Al 2 O 3 TARGETS BOMBARDED BY SLOW Xe + IONS J. C. Rao 1, 2 *, M. Song 2, K. Mitsuishi 2, M. Takeguchi 2, K. Furuya 2 1 Department

More information

Energy Spectroscopy. Excitation by means of a probe

Energy Spectroscopy. Excitation by means of a probe Energy Spectroscopy Excitation by means of a probe Energy spectral analysis of the in coming particles -> XAS or Energy spectral analysis of the out coming particles Different probes are possible: Auger

More information